The present invention is a part of tennis net sporting equipment generally, and specifically relates to permanent and portable devices and straps for adjusting and maintaining the regulation height of a tennis net.
Current U.S. Class:473/495; 24/625Intern'l Class:A63B 061/00Field of Search273/29 BA 24/627, 628, 629, 630, 631, 632,634, 635, 636References cited:U.S. Patent Documents:1239924September 1917Lord273/29.1351066August 1920Robinson273/29.140997March 1920Vaile273/29.1534447April 1925Hardy273/29.3549146December 1970Davis273/29.4247099January 1981Pandak273/29.4671509June 1987Newmann273/29.4831694May 1989Kong 24/635.4973055November 1990Muir273/29.Foreign Patent Documents:190006December 1922GB273/29.344615March 1931GB273/29.516402January 1940GB273/29.2138879October 1984GB 24/634.
A vertical net suspended by a metal cable bisects a tennis court into two equal playing areas. The net and cable are connected to posts (approx. 40 inches) that are taller than the regulation height stipulated for the center of the net (currently 36 inches) during actual play. In preparing the court for play, the cable and net are pulled taut between the two posts and then a net strap anchored to the court surface adjusts the center of the net downward to regulation height and attempts to hold it there. The maintenance of the net at the prescribed height is crucial for fair play, with the slightest variance potentially having a profound impact on the scoring and outcome of a given tennis match. Serious players often carry tape measures to matches with them and spend a great amount of time-both prior to and during play-trying to adjust extant net straps to bring the net to the correct height. In professional matches, the net height is checked periodically by the umpire during a match.
Many forms of net strap exist and a number of different devices have been proposed to correctly measure and maintain tennis nets at the correct height. Muir U.S. Pat. NO. 4,973,055) describes a net strap with an integral measuring system in which two pieces of strapping material are fastened to the court anchor by a double-ended snap hook. One of the straps has a serrated-edge buckle, through which the other strap is fed before it is folded down upon itself and attached to itself by means of hook and loop material. A sliding, interwoven measuring tape device is integral to the net strap and is adequate for measuring the net to the correct height; however, the strap itself does not maintain the net at the correct height over moderate to long periods of time. The buckle system does not sufficiently hold and the serrated edge in the buckle actively degrades the strap material. The sliding, interwoven measuring tape has a “different looks to it that can be distracting, making it unsuitable for professional “tour-level” applications. And importantly, the use of a potentially distracting, visible buckle on a strap made for the center of a court is less than desirable for professional applications. Finally, when the strap is installed, the two parallel bands of the strap (one running on each side of the net) do not interlock through the net; thus the net and net strap are not fully integrated with one another. An important problem facing the professional circuit today is that due to the strap and the net remaining thus distinct, the electronic “let” monitoring devices employed sometimes gives false “let” calls (due, for example, to even a mild wind vibrating the net strap) thus interrupting play, potentially changing the outcome of a point, and in the worst-case scenario altering the outcome of a match. (A “let” is when a served ball touches the net before landing in the opposite court, resulting in the suspension of match play and the serve having to be repeated. The accuracy of a “let call” is of vital important to the professional game, so much so, that electronic vibration monitors, optical devices, and microphones are used alongside human monitors to detect a ball brushing the top of a net.)
Pandak (U.S. Pat. No. 4,247,099) offers another net strap with an integral measuring device comprising a single strap passed through a snap hook with a set of interlocking rings or a Velcro fastener close to each end. The strap is passed over the net and the ends attached to one another. The net is at the correct height when one end of the strap touches the ground and an indicator mark is visible on the top of the net. This simple device correctly measures the net height while the strap is new, but the device has a few major problems. The free (measuring) end of the strap can abrade with time and become frayed during match play (thus negating its usefulness in measuring the correct height of the net); and more importantly, neither the rings not the Velcro sufficiently holds the strap in place. Tennis balls hitting the net cable loosen the Velcro and cause the described simple ring devices to slip, even under recreational play. The fastening systems of Pandak's design are simply inadequate to secure the net at the correct height under the extreme net cable tensions employed by the professional tennis circuit today. Pandak's straps also do not interlock through the net: thus the net and net strap are not integrated with one another, and the problem with potential false “let” calls made by electronic monitoring devices remains.
Newman (U.S. Pat. No. 4,671,509) describes a net strap very similar in design to Muir (U.S. Pat. No. 4,973,055), although without the measuring device. Newman's strap is a single piece of material that is joined with a serrated buckle on one end. The other end is fed through the buckle and folded back onto itself where it is attached with a hook and loop material. The buckle plus the hook and loop work well, together as a fastener for recreational play, but in professional applications, the straps continue to slip. Like the Muir design, as well, though, the buckle is clearly visible from one side of the net. The ideal appearance sought by professional circuits worldwide has historically always been one of uniformity (both sides of the court area should be identical in appearance), with the best possible option for the net strap being a clean, white line (without visible and potentially distracting buckles). The abrasion problem with Muir's serrated buckle occurs with Newman's, as well. This device mandates an exterior measuring device, such as a tape measure or a yardstick be employed, and the height of the net must be measured with such a device each time it is checked. Newman's straps do not interlock through the net: thus the net and net strap are not integrated with one another, and the problem with potential false “let” calls made by electronic monitoring devices remains.
Robinson (U.S. Pat. No. 1,351,066) describes a net strap that is limited in use to court surfaces other than hard courts (the majority of courts in the U.S. are hard courts, such as asphalt or uhard-true,” etc.), because it demands an anchoring peg and chain be driven into the court surface. Although once installed (this takes measuring with an exterior measuring device) it remains at the correct height, the strap forces the destruction of existing regulation court anchors (the standard of which are designed to accept a snap clip), and the chain is a potential distraction. The straps do not interlock through the net: thus the net and net strap are not integrated with one another, and the problem with potential false “let” calls made by electronic monitoring devices remains.
Hardy (U.S. Pat. No. 1,534,447) describes a strap and buckle for holding a tennis net to a prescribed height, but it has no integral measuring system or security systems that prevent slippage under the demands of today's professional circuit. The buckle is, again, a potential distraction. The straps do not interlock through the net: thus the net and net strap are not integrated with one another, and the problem with potential false “let” calls made by electronic monitoring devices remains.
Vaile (U.S. Pat. No. 140,997) describes a center stay for a tennis net which holds the net at 36 inches above the court provided that the court anchor depth never changes from that to which his stay was measured; his device does not allow for what are common deviations in court anchor depths. The straps do not interlock through the net: thus the net and net strap are not integrated with one another, and the problem with potential false “let” calls made by electronic monitoring devices remains.
Davis (U.S. Pat. No. 3,549,146) shows a measuring device attached to a tennis net strap anchor, but like Robinson, this device must be driven into the court surface (thus it can't be used on hard courts) and cannot be adapted to use the anchors already available on most hard and soft courts.
This self-measuring tennis net strap is unique in many ways and overcomes the problems associated with prior net strap inventions. It is adaptable to different court surfaces and anchor configurations and depths. It is easy to install and adjustable, so variances in court anchor depths and net post and cable heights are allowed for. The tab on the free end of the strap keeps the measuring end from fraying and the measuring device from deteriorating.
This self-measuring tennis net strap conforms to the ideal net strap appearance historically sought after by professional tour officials. From both sides of the net, the strap appears only as a clean, white line. The buckle and multiple hook and loop swatches, along with the strap-to-strap connectors are “hidden” inside the installed strap and offer no distraction to players. This strap is extremely durable, of negligibly or non-stretching material with a non-slipping, non-abrading buckle, preferably reinforced by two other fastening systems, in order to effect a heavy-duty strap that can withstand the demands of professional tour applications. The two sides of the installed strap are secured to one another through the net, thus integrating the strap with the net, itself. In addition to making the strap even more secure, this solves the electronic monitoring device false “let” call problem in which vibrations due to external influences other than a tennis ball are recorded, thus interrupting play or potentially influencing the outcome of a match.